SAMPLE. Application of Biochemical Markers of Bone Turnover in the Assessment and Monitoring of Bone Diseases; Approved Guideline

Transcription

1 Archived Document This archived document is no longer being reviewed through the CLSI Consensus Document Development Process. However, this document is technically valid as of September Because of its value to the laboratory community, it is being retained in CLSI s library. Application of Biochemical Markers of Bone Turnover in the Assessment and Monitoring of Bone Diseases; Approved Guideline This guideline provides information on how biochemical markers of bone turnover can be applied to facilitate and harmonize data interpretation and to help answer clinical questions in the area of bone diseases. July 2004 A guideline for global application developed through the Clinical and Laboratory Standards Institute consensus process.

2 Clinical and Laboratory Standards Institute Setting the standard for quality in medical laboratory testing around the world. The Clinical and Laboratory Standards Institute (CLSI) is a not-for-profit membership organization that brings together the varied perspectives and expertise of the worldwide laboratory community for the advancement of a common cause: to foster excellence in laboratory medicine by developing and implementing medical laboratory standards and guidelines that help laboratories fulfill their responsibilities with efficiency, effectiveness, and global applicability. Consensus Process Consensus the substantial agreement by materially affected, competent, and interested parties is core to the development of all CLSI documents. It does not always connote unanimous agreement, but does mean that the participants in the development of a consensus document have considered and resolved all relevant objections and accept the resulting agreement. Commenting on Documents CLSI documents undergo periodic evaluation and modification to keep pace with advancements in technologies, procedures, methods, and protocols affecting the laboratory or health care. CLSI s consensus process depends on experts who volunteer to serve as contributing authors and/or as participants in the reviewing and commenting process. At the end of each comment period, the committee that developed the document is obligated to review all comments, respond in writing to all substantive comments, and revise the draft document as appropriate. Comments on published CLSI documents are equally essential, and may be submitted by anyone, at any time, on any document. All comments are managed according to the consensus process by a committee of experts. Appeals Process When it is believed that an objection has not been adequately considered and responded to, the process for appeals, documented in the CLSI Standards Development Policies and Processes, is followed. All comments and responses submitted on draft and published documents are retained on file at CLSI and are available upon request. Get Involved Volunteer! Do you use CLSI documents in your workplace? Do you see room for improvement? Would you like to get involved in the revision process? Or maybe you see a need to develop a new document for an emerging technology? CLSI wants to hear from you. We are always looking for volunteers. By donating your time and talents to improve the standards that affect your own work, you will play an active role in improving public health across the globe. For additional information on committee participation or to submit comments, contact CLSI. Clinical and Laboratory Standards Institute 950 West Valley Road, Suite 2500 Wayne, PA USA P: F: standard@clsi.org

3 ISBN Vol. 24 No. 22 Replaces C48-P ISSN Vol. 23 No. 26 Application of Biochemical Markers of Bone Turnover in the Assessment and Monitoring of Bone Diseases; Approved Guideline Volume 24 Number 22 Hubert Vesper, Ph.D. Felicia Cosman, M.D. David B. Endres, Ph.D., FACB, DABCC Patrick Garnero, Ph.D. Nicholas R. Hoyle, Ph.D. Michael Kleerekoper, M.D., FACB Nancy J. S. Mallinak Abstract Bone markers are useful tools for the management of bone diseases, because they provide information that is different but complementary to bone mineral density (BMD) measurement. Problems in the measurement and interpretation of bone marker values are still hampering the optimal utility of this clinical tool. Most of these difficulties originate from problems related to the handling and control of analytical and biological variability of bone marker measurements. These sources of variability can be substantial and need to be controlled. In this context, certain applications of bone marker testing may have different requirements for the handling and control of these sources of variability. Finally, certain bone markers or bone marker tests may require special considerations, such as analyte stability. This document addresses these issues and provides information related to applications of bone marker measurements. Clinical and Laboratory Standards Institute (CLSI). Application of Biochemical Markers of Bone Turnover in the Assessment and Monitoring of Bone Diseases; Approved Guideline. CLSI document (ISBN ). Clinical and Laboratory Standards Institute, 950 West Valley Road, Suite 2500, Wayne, Pennsylvania USA, The Clinical and Laboratory Standards Institute consensus process, which is the mechanism for moving a document through two or more levels of review by the health care community, is an ongoing process. Users should expect revised editions of any given document. Because rapid changes in technology may affect the procedures, methods, and protocols in a standard or guideline, users should replace outdated editions with the current editions of CLSI documents. Current editions are listed in the CLSI catalog and posted on our website at If your organization is not a member and would like to become one, and to request a copy of the catalog, contact us at: Telephone: ; Fax: ; customerservice@clsi.org; Website:

4 Number 22 Copyright 2004 Clinical and Laboratory Standards Institute. Except as stated below, any reproduction of content from a CLSI copyrighted standard, guideline, companion product, or other material requires express written consent from CLSI. All rights reserved. Interested parties may send permission requests to permissions@clsi.org. CLSI hereby grants permission to each individual member or purchaser to make a single reproduction of this publication for use in its laboratory procedure manual at a single site. To request permission to use this publication in any other manner, permissions@clsi.org. Suggested Citation CLSI. Application of Biochemical Markers of Bone Turnover in the Assessment and Monitoring of Bone Diseases; Approved Guideline. CLSI document. Wayne, PA: Clinical and Laboratory Standards Institute; Previous Edition: October 2003 Reaffirmed: July 2016 Archived: September 2016 ISBN ISSN ii

5 Volume 24 Contents Abstract... i Committee Membership... iii Foreword... vii 1 Scope Standard Precautions Definitions Applications of Bone Marker Testing Comparing Results with a Reference Range Applications Used to Monitor Changes Over Time in an Individual Applications Linked to Results and Outcomes of Clinical Trials and Epidemiological Studies Factors Affecting Measurement of Bone Markers and Result Interpretation Preanalytical Factors Analytical Factors Postanalytical Factors Special Consideration on Certain Bone Markers Analyte Stability and Specimen Handling... 9 References Appendix A. Diseases, Conditions, and Other Factors Known to Alter Bone Marker Concentrations Appendix B. Exclusion and Partitioning Criteria for Selection of Reference Populations Appendix C. Assay Description and Characteristics of Available Bone Markers Appendix D. Manufacturer-Provided Data for Within-Subject Variability Appendix E. Analyte Stability Appendix F. Recommended Websites Summary of Delegate Comments and Subcommittee Responses The Quality System Approach Related NCCLS Publications v

6 Volume 24 Foreword Bone, as a structural tissue, is subject to stress damage that can eventually lead to fracture if allowed to progress. However, bone has the ability to repair itself by a process called bone remodeling which consists of removal of older bone tissue (resorption) and replacement with new bone tissue (formation). Resorption and formation are interdependent, and the processes always begin with resorption of bone on the skeletal surface forming a resorption cavity. The cells responsible for resorption are osteoclasts. Bone formation begins when the resorption cavity is complete with deposition of bone matrix, 90% of which is Type I collagen followed by mineralization of this matrix with hydroxyapatite (see Figure 1). Through the first ten years of human growth, bone remodeling is accelerated and formation exceeds remodeling. Both processes are in balance during the second to approximately the fourth decade of life. Then, beginning about the fifth decade of life, resorption slightly exceeds formation, resulting in a net negative balance. Consequently, anything that accelerates the rate of remodeling also accelerates bone loss. Menopause is the most prevalent cause of accelerated bone loss. Osteoblast Formation 13 weeks Figure 1. The Bone Remodeling Cycle Resorption Osteoclast Bone status can be described by measuring bone mineral density, which provides information on both bone mineral content and bone fragility. Bone mineral density measurement, however, does not provide data on the rate of bone remodeling (whether formation exceeds or lags resorption). This information is obtained, qualitatively, by measuring biochemical bone markers (the biochemical substance produced or released during bone turnover). Both measurements complement each other and are needed to get a clear understanding of bone status. For example, while bone mineral density provides information about current bone status such as normal bone, osteopenic bone or osteoporotic bone, high bone marker values over an extended period of time indicate that the determined bone mineral density will decrease. Several approaches listed in Table 1 have been developed to evaluate bone status in patients with metabolic bone diseases. Table 1. Useful Methods in the Evaluation of Common Bone Diseases Disease Bone Mineral Density Radiograph (X-Ray) Radionuclide Scan Biochemical Bone Markers Osteoporosis + +* + Paget s Disease Primary + +* + Hyperparathyroidism Osteomalacia Metastatic Bone Disease * if fractures are suspected + method normally used for evaluation of disease method normally not used for evaluation of disease vii

7 Number 22 While three of the methodologies mentioned in Table 1 provide information primarily about bone macrostructure, integrity, and quantity, only bone marker data provides information about bone turnover. BMD measurement provides data on the cumulative benefits and liabilities to the skeleton over the years; whereas bone markers provide information on the current metabolism of the whole skeleton. Bone marker measurements have the advantage that changes in bone marker concentrations can also be seen earlier than changes in bone mineral density. For example, one study identified a response to antiresorptive treatment using bone mineral density measurement after one year (indicated by a 3% increase from baseline) and using osteocalcin as bone markers after three months (indicated by a -20% change from baseline). 1 Furthermore, changes in BMD measurements with osteoporosis do not always fully predict the observed effect on fracture risk. 2 Bone markers can be measured in blood and urine and fall into two categories: (a) enzymes or other proteins secreted by osteoblasts or osteoclasts; and (b) substances produced during the formation or breakdown of Type I collagen, the primary protein forming the organic matrix in bone. 2 The markers of bone resorption are degradation products of bone. Both bone mineral (primarily calcium) and bone matrix (primarily Type I collagen) are broken down and released into the bloodstream. Type I collagen consists of two α 1 and one α 2 molecules in a triple helix arrangement with the amino- and carboxy-terminal ends of the triple helix comprising a straight portion of the molecule known as a telopeptide. The telopeptide of one molecule of collagen is linked to the helical portion of an adjacent molecule by crosslinking molecules including deoxypyridinoline (DPD) and pyridinoline (PYD) (see Figure 2). Both pyridinium crosslinks can be found in other collagen tissues such as cartilage, blood vessels, or ligaments. However, they are the major crosslinks in bone with DPD occurring mainly in bone collagen. Because of the higher turnover of bone collagen compared to other collagen, both markers are considered markers for bone resorption. 3 The amino-terminal telopeptide, carboxy-terminal telopeptide, DPD, and PYD are released into the bloodstream during resorption. They are then rapidly filtered by the kidney and released into the urine where they can be measured. One marker of bone resorption (not released from bone but from osteoclasts) is tartrate-resistant acid phosphatase isoform 5b (TRACP 5b). Figure 2. The Structure of Bone Collagen Depicting the Helical and Telopeptide Regions and the Crosslinks Between the Collagen Molecules. From Watts NB. Clinical utility of biochemical markers of bone remodeling. Clin Chem. 1999;45: Reprinted with permission from the American Association of Clinical Chemistry. viii

8 Volume 24 Markers of bone formation are products released by the osteoblasts such as osteocalcin and bone-specific alkaline phosphatase, or are peptides derived from the amino-terminal or carboxy-terminal of Type I procollagen, a precursor of Type I collagen. Markers of bone formation are measured in serum only. Osteocalcin is secreted by the osteoblast and incorporated into the bone matrix from which it is released during bone resorption. Results of bone markers reported from large epidemiological or clinical trials are sometimes difficult to interpret for everyday clinical situations, i.e., the individual often has more than one disease that may affect bone turnover. Like other clinical parameters (e.g., blood lipids), analytic and biologic variability of bone markers can be significant and need to be considered when they are used. 4,5 Therefore, as with any clinical analyte, the use of bone markers requires special considerations at preanalytical, analytical, and postanalytical stages of testing. Physicians and laboratorians must understand the limitations of bone marker measurements, while appreciating their clinical utility. 6,7 The reader is referred to a number of websites for specific guidelines on the use of biochemical markers of bone remodeling in clinical practice. A list, included as Appendix F, is not exhaustive but does acknowledge that many national and international organizations have addressed this question to varying degrees. It is recommended that the reader locate the website of the relevant osteoporosis organization in his/her country for more complete local information. A Note on Terminology NCCLS, as a global leader in standardization, is firmly committed to achieving global harmonization wherever possible. Harmonization is a process of recognizing, understanding, and explaining differences while taking steps to achieve worldwide uniformity. NCCLS recognizes that medical conventions in the global metrological community have evolved differently in the United States, Europe, and elsewhere; that these differences are reflected in NCCLS, ISO, and CEN documents; and that legally required use of terms, regional usage, and different consensus timelines are all obstacles to harmonization. Despite these obstacles, NCCLS recognizes that harmonization of terms facilitates the global application of standards and is an area that needs immediate attention. Implementation of this policy must be an evolutionary and educational process that begins with new projects and revisions of existing documents. In keeping with NCCLS s commitment to align terminology with that of ISO, the following describes the metrological terms and their use in : The term accuracy refers to the closeness of the agreement between the result of a (single) measurement and a true value of a measurand and comprises both random and systematic effects. Trueness is used in this document when referring to the closeness of the agreement between the average value from a large series of measurements and to a true value of a measurand; the measurement of trueness is usually expressed in terms of bias. Precision is defined as the closeness of agreement between independent test/measurement results obtained under stipulated conditions. As such, it cannot have a numerical value, but may be determined qualitatively as high, medium, or low. For its numerical expression, the term imprecision is used, which is the dispersion of results of measurements obtained under specified conditions. In addition, different components of precision are defined in, primarily repeatability, i.e., the closeness of the agreement between results of successive measurements of the same measurand carried out under the same conditions of measurement; while reproducibility describes the closeness of agreement of results of measurements under changed conditions. Key Words Biological variability, bone marker, preanalytical variability ix

9 Volume 24 Application of Biochemical Markers of Bone Turnover in the Assessment and Monitoring of Bone Diseases; Approved Guideline 1 Scope Biochemical bone marker tests are increasingly used in the management of metabolic bone diseases. They provide valuable information when performed in research centers dealing with osteoporosis and bone metabolism under well-controlled conditions and experienced personnel. However, their use in general, less specialized institutions in treating individual patients appears to be difficult, 2,8-10 and has hampered the broad use of bone markers as a clinical tool. This situation is partially due to the lack of guidance on managing and controlling biological variation and appropriate preanalytical specimen handling. Guidance is also needed for applying and using findings from clinical trials and epidemiological studies for data interpretation. Bone markers exhibit substantial short-term and long-term fluctuations related to time of day, phase of the menstrual cycle, season of the year, diet, exercise, and other factors known to alter bone remodeling. These biological factors produce significant within-subject and between-subject variability in markers, in addition to assay imprecision and method bias. To minimize this variability, preanalytical, analytical, and postanalytical factors need to be considered and testing procedures harmonized. This document will guide laboratorians and clinicians in selecting and using bone markers for assessing and monitoring metabolic bone diseases. Guidance is provided on managing and controlling biological variation, appropriate preanalytical sample handling, postanalytical reporting of results, and applying findings from clinical trials and epidemiological studies for data interpretation. The document will be useful to both laboratorians and healthcare providers involved in the care of patients with bone diseases, as well as to individuals and organizations involved in developing and conducting clinical studies. In addition, this document is a starting point for discussions about further harmonization of bone marker testing. Although efforts have been undertaken to use markers of bone metabolism in the management of related diseases such as cancer or arthritis, 8-11 such applications are not considered in this document, nor does this guideline provide information about the management of the disease with regard to medications and other forms of patient care. Such clinical guidelines need to be developed separately by the appropriate organizations. This guideline focuses on the following bone markers: Formation Markers Osteocalcin Total and bone alkaline phosphatase Type I collagen propeptides Resorption Markers Pyridinoline and deoxypyridinoline Type I collagen telopeptides a Tartrate resistant acid phosphatase isoform 5b a Comprising C-terminal crosslinking telopeptide of Type I collagen and N-terminal crosslinking telopeptides of Type I collagen. Clinical and Laboratory Standards Institute. All rights reserved. 1

10 Number 22 2 Standard Precautions Because it is often impossible to know what might be infectious, all patient and laboratory specimens are treated as infectious and handled according to standard precautions. Standard precautions are guidelines that combine the major features of universal precautions and body substance isolation practices. Standard precautions cover the transmission of all infectious agents and thus are more comprehensive than universal precautions which are intended to apply only to transmission of blood-borne pathogens. Standard and universal precaution guidelines are available from the U.S. Centers for Disease Control and Prevention (Guideline for Isolation Precautions in Hospitals. Infection Control and Hospital Epidemiology. CDC. 1996;17(1):53-80 and MMWR 1988;37: ). For specific precautions for preventing the laboratory transmission of all infectious agents from laboratory instruments and materials and for recommendations for the management of exposure to all infectious disease, refer to the most current edition of NCCLS document M29 Protection of Laboratory Workers from Occupationally Acquired Infections. 3 Definitions A variety of abbreviations and acronyms are currently used for bone markers. To avoid misunderstandings and confusion in the literature, the subcommittee suggests the use of names and abbreviations recommended by the expert committee for the Committee of Scientific Advisors of the International Osteoporosis Foundation. 9 Accuracy (of measurement) Closeness of the agreement between the result of a measurement and a true value of the measurand (VIM93) 12 ; NOTE: See the definition of Measurand. Between-subject variation Variation in analyte concentrations among individuals because of differences in factors that cannot be altered within an individual or that last for an extended period of time; NOTE: This includes factors such as age, sex, race, genetics, or long-term health status. Bias The difference between the expectation of the test results and an accepted reference value (ISO ). 13 Bone alkaline phosphatase, bone ALP An enzyme found in osteoblasts; NOTES: a) It has a molecular weight of approximately Da; b) It is distinguishable from other alkaline phosphatases by its oligosaccharide side chain. Bone formation The deposition of new bone, including bone mineral and bone matrix components. Bone marker Biochemical substance produced or released during bone turnover; NOTE: It can be measured in urine, blood, or other body fluids. Bone resorption The process of removal of bone tissue, including bone mineral and bone matrix components. C-terminal crosslinking telopeptide of Type I collagen, CTX Peptides that are formed during collagen degradation, originating from the C-terminal telopeptide of collagen molecules. Deoxypyridinoline, DPD//Lysylpyridinoline Pyridinium compound formed during collagen maturation by crosslinking lysine and hydroxylysin side chains from different collagen molecules. Imprecision Dispersion of independent results of measurements obtained under specified conditions; NOTE: It is expressed numerically as standard deviation or coefficient of variation. 2 Clinical and Laboratory Standards Institute. All rights reserved.

11 Number 22 The Quality System Approach NCCLS subscribes to a quality system approach in the development of standards and guidelines, which facilitates project management; defines a document structure via a template; and provides a process to identify needed documents through a gap analysis. The approach is based on the model presented in the most current edition of NCCLS HS1 A Quality System Model for Health Care. The quality system approach applies a core set of quality system essentials (QSEs), basic to any organization, to all operations in any healthcare service s path of workflow. The QSEs provide the framework for delivery of any type of product or service, serving as a manager s guide. The quality system essentials (QSEs) are: Documents & Records Equipment Information Management Process Improvement Organization Purchasing & Inventory Occurrence Management Service & Satisfaction Personnel Process Control Assessment Facilities & Safety addresses the quality system essentials (QSEs) indicated by an X. For a description of the other NCCLS documents listed in the grid, please refer to the Related NCCLS Publications section on the next page. Documents & Records Organization Personnel Equipment Purchasing & Inventory Process Control X C28 EP14 Information Management Occurrence Management Adapted from NCCLS document HS1 A Quality System Model for Health Care. Path of Workflow Assessment Process Improvement Service & Satisfaction Facilities & Safety GP29 GP27 M29 A path of workflow is the description of the necessary steps to deliver the particular product or service that the organization or entity provides. For example, GP26-A2 defines a clinical laboratory path of workflow which consists of three sequential processes: preanalytic, analytic, and postanalytic. All clinical laboratories follow these processes to deliver the laboratory s services, namely quality laboratory information. addresses the clinical laboratory path of workflow steps indicated by an X. For a description of the other NCCLS documents listed in the grid, please refer to the Related NCCLS Publications section on the next page. Patient Assessment X Preanalytic Analytic Postanalytic Test Request Specimen Collection X H3 GP16 Specimen Transport Specimen Receipt Testing Review Laboratory Interpretation Results Report Post-test Specimen Management X GP16 X X X X Adapted from NCCLS document HS1 A Quality System Model for Health Care. 32 Clinical and Laboratory Standards Institute. All rights reserved.

12 Volume 24 Related NCCLS Publications * C28-A2 EP14-A How to Define and Determine Reference Intervals in the Clinical Laboratory; Approved Guideline Second Edition (2000). This document provides guidance for determining reference values and reference intervals for quantitative clinical laboratory tests. Evaluation of Matrix Effects; Approved Guideline (2001). This document provides guidance for evaluating the error or bias in analyte measurements that is due to the sample matrix (physiological or artificial) due to the sample matrix (physiological or artificial) when two analytical methods are compared. GP16-A2 Routine Urinalysis and Collection, Transportation, and Preservation of Urine Specimens; Approved Guideline Second Edition (2001). This guideline describes routine urinalysis test procedures that address materials and equipment, macroscopic examinations, clinical analyses, and microscopic evaluations. GP27-A Using Proficiency Testing (PT) to Improve the Clinical Laboratory; Approved Guideline (1999). This guideline provides assistance to laboratories in using proficiency testing as a quality improvement tool. GP29-A Validation of Laboratory Tests When Proficiency Testing is Not Available; Approved Guideline (2002). This guideline will suggest workable alternatives for evaluating the accuracy of an assay when standard interlaboratory comparison programs are unavailable. H3-A5 Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture; Approved Standard Fifth Edition (2003). This document provides procedures for the collection of diagnostic specimens by venipuncture, including line draws, blood culture collection, and venipuncture in children. It also includes recommendations on order of draw. M29-A2 Protection of Laboratory Workers from Occupationally Acquired Infections; Approved Guideline Second Edition (2001). This document provides guidance on the risk of transmission of hepatitis viruses and human immunodeficiency viruses in any laboratory setting; specific precautions for preventing the laboratory transmission of blood-borne infection from laboratory instruments and materials; and recommendations for the management of blood-borne exposure. * Proposed- and tentative-level documents are being advanced through the NCCLS consensus process; therefore, readers should refer editions. to the most recent Clinical and Laboratory Standards Institute. All rights reserved. 33

13 E PL Explore the Latest Offerings From CLSI! As we continue to set the global standard for quality in laboratory testing, we are adding products and programs to bring even more value to our members and customers. M By becoming a CLSI member, your laboratory will join 1,600+ other influential organizations all working together to further CLSI s efforts to improve health care outcomes. You can play an active role in raising global laboratory testing standards in your laboratory, and around the world. SA Find out which membership option is best for you at Find what your laboratory needs to succeed! CLSI U provides convenient, cost-effective continuing education and training resources to help you advance your professional development. We have a variety of easy-to-use, online educational resources that make elearning stress-free and convenient for you and your staff. See our current educational offerings at When laboratory testing quality is critical, standards are needed and there is no time to waste. eclipse Ultimate Access, our cloud-based online portal of the complete library of CLSI standards, makes it easy to quickly find the CLSI resources you need. Learn more and purchase eclipse at clsi.org/eclipse. For more information, visit today.

14 950 West Valley Road, Suite 2500, Wayne, PA USA P: Toll Free (US): F: ISBN E: